Changes between Version 3 and Version 4 of notes


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Timestamp:
09/18/08 12:26:45 (11 years ago)
Author:
daley
Comment:

some FLASH info

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  • notes

    v3 v4  
    1212NOTE: These configurations require code that is not part of the current public FLASH distribution. 
    1313 
     14=== FLASH userguide === 
     15 
     16The FLASH userguide is available at: 
     17http://flash.uchicago.edu/website/codesupport/flash3_ug/ 
     18 
     19The important sections are: 
     202. Quick Start 
     213.6 The runtime parameter file (flash.par) 
     225. The FLASH configuration script (setup) 
     2322. Timer and Profiler Units 
     24 
    1425=== FLASH setup information === 
    15 (Still to come). 
     26 
     27FLASH uses PARAMESH to manage the oct-tree AMR grid.  An important 
     28parameter in this distributed data structure is MAXBLOCKS which 
     29indicates the maximum number of blocks per processor.  It is 
     30particularly relevant in limited memory environments because this 
     31static memory allocation can be very large.  Its value can be adjusted 
     32by passing the -maxblocks option to the setup script, e.g. 
     33 
     34-maxblocks=100 
     35 
     36=== Using TAU with FLASH === 
     37 
     38FLASH has setup support for instrumenting each subroutine using the 
     39TAU toolkit.  Simply pass the full-path of a TAU makefile in the -tau 
     40option of the setup script, e.g. 
     41 
     42-tau=/soft/apps/tau/tau_latest/bgp/lib/Makefile.tau-multiplecounters-mpi-papi-pdt 
     43 
     44This instructs setup to replace the compilers in Makefile.h with the 
     45TAU wrapper compiler scripts, and also to copy the TAU instrumentation 
     46file at tools/tau/select.tau into the object directory.  The 
     47select.tau file excludes certain subroutines from TAU instrumentation. 
     48Please note, some of the subroutines may be excluded unnecessarily as 
     49the list was constructed using an older version of FLASH with older 
     50versions of the TAU software stack. 
     51 
     52=== FLASH timers === 
     53 
     54FLASH has in-built timers giving timing information for labelled code 
     55sections.  These are switched on by default, but they can be switched 
     56off by replacing them with a stub implementation at setup time.  This 
     57is done by passing the following line to the setup script: 
     58 
     59--without-unit=monitors/Timers/TimersMain 
     60 
     61 
     62As an alternative, a custom timer implementation has been written. 
     63This times the labelled code sections in FLASH using TAU 
     64timers and not the in-built FLASH timers.  Timing data for any 
     65labelled code section therefore appears alongside routine level data 
     66in the TAU profile, e.g. 
     67 
     68[chris@hplaptop MULTI__GET_TIME_OF_DAY]$ pprof -p -n 20 -s 
     69Reading Profile files in profile.* 
     70 
     71FUNCTION SUMMARY (total): 
     72--------------------------------------------------------------------------------------- 
     73%Time    Exclusive    Inclusive       #Call      #Subrs  Inclusive Name 
     74              msec   total msec                          usec/call  
     75--------------------------------------------------------------------------------------- 
     76100.0         27.3      7829590          32          96  244674686 FLASH  
     77 59.6         48.2      4663871          32         224  145745970 DRIVER_EVOLVEFLASH  
     78 57.7         1145      4516119          32        6410  141128734 *** custom:evolution  
     79 40.4         2155      3165100          32       14603   98909381 DRIVER_INITFLASH  
     80 40.0          148      3130132          32         768   97816632 *** custom:initialization  
     81 39.2          218      3071459         640         640    4799155 *** custom:hydro  
     82 39.2          325      3071241         640        1280    4798813 HYDRO  
     83 39.2          657      3070915        1280        2560    2399152 HY_PPM_SWEEP  
     84 31.9         29.2      2493992          32         128   77937243 GRID_INITDOMAIN  
     85 31.8          329      2493440          32        1741   77920004 GR_EXPANDDOMAIN  
     86 
     87"*** custom:" prefix indicates a FLASH labelled section. 
     88 
     89This can be included in a FLASH simulation by passing the following 
     90line to the setup script: 
     91 
     92--with-unit=monitors/Timers/Tau 
     93 
     94(Please note, the timer implementation is not in the tar ball we sent 
     95you, but it will be available when we create the PERI svn branch).